GPS - Using Virtual COM port in .NET Framework
There is a limitation on u-blox GPS VCP (Virtual COM port) driver, that does not fully emulate a hardware serial port. Therefore, it may not be possible to open the Virtual COM port (for example "COM3") in applications using the .NET Framework.
Please utilize the u-blox CDC driver instead of the u-blox VCP driver.
Here you will find instructions on how to install the u-blox CDC driver as well as the u-blox CDC driver download: KB23643